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UefiCpuPkg/MpInitLib: Use AsmCpuidEx() for CPUID_EXTENDED_TOPOLOGY leaf

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The CPUID_EXTENDED_TOPOLOGY CPUID leaf takes a subleaf as input when
returning CPUID information. However, the AsmCpuid() function does not
zero out ECX before the CPUID instruction, so the input leaf is used as
the sub-leaf for the CPUID request and returns erroneous/invalid CPUID
data, since the intent of the request was to get data related to sub-leaf
0. Instead, use AsmCpuidEx() for the CPUID_EXTENDED_TOPOLOGY leaf.

Fixes: d4d7c9ad5fe5 ("UefiCpuPkg/MpInitLib: use BSP to do extended ...")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
This commit is contained in:
Tom Lendacky 2023-11-07 06:45:30 +08:00 committed by mergify[bot]
parent d451bba399
commit 447798cd3a
1 changed files with 8 additions and 1 deletions
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9
UefiCpuPkg/Library/MpInitLib/AmdSev.c
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@ -256,7 +256,14 @@ FillExchangeInfoDataSevEs (
if (StdRangeMax >= CPUID_EXTENDED_TOPOLOGY) {
CPUID_EXTENDED_TOPOLOGY_EBX ExtTopoEbx;
AsmCpuid (CPUID_EXTENDED_TOPOLOGY, NULL, &ExtTopoEbx.Uint32, NULL, NULL);
AsmCpuidEx (
CPUID_EXTENDED_TOPOLOGY,
0,
NULL,
&ExtTopoEbx.Uint32,
NULL,
NULL
);
ExchangeInfo->ExtTopoAvail = !!ExtTopoEbx.Bits.LogicalProcessors;
}
}